The coldest hidden world: What lies beneath Antarctica?

The coldest, driest, highest and windiest continent on the planet; Antarctica is a home of extremes. Antarctica is a frozen windswept place of unique landscape, distinctive ecosystems and is one of the world’s true wildernesses.

A freezing wonderland

Antarctica is the southernmost continent on Earth; and one of the least visited and explored places. With some of the coldest temperatures on the planet it is not a shock that Antarctica is a continent capped by an inland ice sheet up to 4.8m thick which contains up to 90% of the world’s freshwater. Most famously it contains the geographical South Pole which is 1235km from the closest coastline. This is the coldest temperature extreme with temperatures reaching as cold as -75°C, with an even colder world record -89°C recorded from the Antarctic station, Vostok.

Antarctica is most definitely a continent for science and research, between 28 countries there are about 70 research stations spread across the continent. 40 of these operating year round. One of the British research, Halley Research Station is shown to the left (Figure 2). Antarctica BAS scientists usually only work there in the summer months because of the harsh weather conditions of Antarctica.

What lies underneath?

Buried under kilometers of ice is a fascinating realm of canyons, waterways and lakes, which is only now being mapped in detail. Recently scientists have begun exploring beneath the ice to begin an understanding of what lies beneath. The British Antarctic Survey have many mapping initiatives and BEDMAP is a major creativity that has compiled the bed topography of the Antarctic as can be seen in the image below (Figure 3).

As can be seen in this image; the Antarctic Peninsula, the extended point extending northwards from the Antarctic continent is a chain of mountains projecting from the west coast. The western part of Antarctica has the least features as seen in figure 3 but is of great scientific interest as it is loosing ice faster than anywhere else on Antarctica with some of the glaciers shrinking by more than 1 meter per year. The largest zone of Antarctica is East Antarctica and as can be seen in the BEDMAP 2 it is the most varied environment with flatter plains and shield areas as well as some mountains in this area.

In a place filled with frozen water it is surprising that there are more than 400 known lakes all hidden under the ice as can be seen in figure 4, with more being discovered. Beneath this ice the water lubricates the boundary of the ice sheet and its rocky bed and so therefore controls the flow and actions of the ice itself.

How these features are able to exist under such large volumes of ice is pressure.The water is able to stay liquid because of the pressure of the overlaying large weight of ice pushing on the water. So it is able to stay as a liquid even when the temperatures are below the normal freezing point. In addition the ice on top of this water actually insulates, and so protects it from the harsh environment and freezing temperatures above the ice. The water for the lakes is created by the heat from the Earths core and also friction that is generated from ice flows.

Lake Vostok

Figure 5. Lake Vostok: it took a long time to bore down to these waters but the findings were definitely revolutionary Source – Extreme Tech

Lake Vostok is the largest of the Antarctic lakes and is the world’s sixth largest lake by volume. Hidden under approximately 4000 meters of ice is the huge 12,500 square kilometres (4,830 square miles) Lake Vostok averaging depths of 430 metres. Using ice penetrating radar and seismic techniques scientists have been able to map Lake Vostok to understand its origins with results showing that it may be up to 15 million years old. The lake has circulation patterns driven by freezing and thawing of the overlying ice.

The Vostok ice core in central Antarctica has provided the longest record of past changes in climate and atmospheric composition, showing four glacial-interglacial cycles down to a depth of 3310m.

First broken and explored in 2012 by the Russians, Lake Vostok has provided samples, most likely to be taken from a pocket of water just above the lake. The process began as an ice coring effort to examine ancient climatic conditions. Figure 5 shows a diagram of a cross section from the station down to where the lake is located. There was suspicions since the early 1990,s that the lake existed and was discovered in 1992 but plans to drill down and explore this area took a long time to develop but as technologies increases and more knowledge of the area gained, eventually in 2012 there was success. And again recently in 2015, Lake Vostok has been cracked again providing even more samples this time from the pristine lake water.

More wonders

Under the ice of Antarctica there are still more features and structures and is home to the worlds largest canyon system. It is only this year that, what is thought to be Antarctica’s second largest lake has been observed. It is located under the ice sheet in Princess Elizabeth Land in East Antarctica. The lake was discovered after researchers noticed that ice at the surface was disturbed and grooved which indicates that liquid water is below. This lake is connected to a large canyon system which is now known as the worlds largest.

Discovered in January earlier this year is the world’s biggest canyon measuring 683 miles long, making it bigger than the UK. Previously the longest canyon was found in 2013, another under ice feature in Greenland. This was measured at 460 miles long. Extensive research on this canyon system has been conducted by Dr Stuart Jamieson of Durham University; the video below shows the recent research including mapping of the canyon system.

What was once thought to be a vast nothingness in terms of environment and features has been discovered to be the complete opposite. Huge features have been found in this hidden world under the ice of Antarctica. What is even more exciting about this topic is the fact that it is still so undiscovered and still in the early exploration stages currently. With advancing technology and increased knowledge what else could be found in these new environments. Is there the possibility that life could be found? What these environments will develop into is definitely something to determine.

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Extreme marine habitats is a site dedicated to those habitats that are simply extreme! Written by students, we aim to provide detailed and insightful information on a variety of marine science subjects.